Electronic Design
Solid-State Lighting Still Inching Its Way Home

Solid-State Lighting Still Inching Its Way Home

Another year has passed and still there’s little sign of solid-state lighting (SSL) dominating the home, workplace, schools, or anywhere else other than signage applications. But before going further, keep in mind that we’re speaking of illumination and not every possible app associated with LEDs, such as backlighting.

Once again, the most common impedance to SSL migration is cost. However, prices have dropped on many LED-based lighting products, based on retail comparisons. These price drops aren’t groundshaking or enough to inspire a rush on the stores, but they are enough to signal a turnaround.

SSL Prices: Deal Or No Deal?

Aside from lowering the price and/or issuing environmental/governmental mandates, what singular approach can OEMs take to accelerate the market’s acceptance and adoption of SSL?

“These are the two key points: lowering the price and/or issuing environmental/governmental mandates,” says Jordon P. Papanier, marketing manager at LEDtronics. “Another requirement is more lumens pet watt for LED chips. Now they range between 50 lumens per watt to 80 lumens per watt in mass production. It is still difficult to get the lumens you need for an A19 bulb package size and have room for the required heatsink with the LEDs that are available today.”

Michael Schratz, director of marketing at Dialight, believes consumer education is key.

“The most important factors to accelerate market acceptance are market education on LED technology and how to compare ‘apples to oranges’ with traditional lighting technologies and the recognition of those implementing the technology to consider all factors and costs considered when reviewing a lighting installation’s total cost of ownership,” Schratz says.

Kee Yean Ng, worldwide product marketing manager for SSL at Avago Technologies, points to product knowledge as well.

“Improving the credibility of LED technology in SSL can help accelerate market acceptance, Ng says. “Discrepancies between claimed performance and actual performance must be eliminated. Equivalency statements to traditional light sources should be accurate. For example, an LED bulb with equivalency claims to a 60-W incandescent bulb might not be correct upon inspection of the photometric output. Standardization of information is important to enable the user to compare performance fairly.”

Don Emmons, CEO of Lumiette, says better lighting quality and product aesthetics are key to SSL adoption.

“They \\[OEMs\\] must improve the light quality and appearance of their products,” Emmons says. “Currently, most LED lighting products have irritating blue-white color temperature at 3500K to 6100K. Consumers are used to and prefer 2700K (incandescent) and 2950K (PAR lamp) color temperature. Additionally, residential consumers do not like the unattractive heatsinks needed to manage the high level of heat generated by LEDs.”

Rob Rix, vice president of lighting at Tyco Electronics Connectivity, also fingers aesthetics.

“The OEMs can speed the adoption of SSL by designing fixtures that take advantage of the small, flat form factor of the LED,” Rix says. “Additionally, adding controls will provide additional efficiencies.”

Jackie Mancini, industrial market director at Bourns, takes a proactive design approach to the issue.

“The most important thing OEMs can do to accelerate the market’s adoption of LED/SSL is to work closely with lighting designers to ensure sound design practices. For instance, when designing the power supplies, it is important to pay attention to over-current and over-voltage threats, as well as design for effective thermal management,” Mancini says.

“Another crucial consideration is the effect of open LEDs on lighting performance, all of which have a significant influence on the life and quality of the lighting,” she continues. “LED/SSL installations must be successful and live up to published expectations, and this, more than anything else, will help to accelerate the market’s acceptance and adoption of solid-state lighting.”

A Modular Approach

In addition to chopping down the price, making a unique product easy to use definitely isn’t a bad idea when going for mass approval. Some designers and companies foresee a modular approach as an absolutely necessary strategy for speeding up SSL adoption. They believe creating luminaires that fit existing fixtures, be they incandescent, fluorescent, halogen, or unique installations, will create a familiar environment for the general public. Obviously this makes sense because of the plethora of existing infrastructure. But will this elicit enough confidence from the public to speed SSL adoption?

“It makes sense that SSL should be built around the well-established infrastructure for general lighting, as this provides an easier path to penetrate general lighting applications,” Ng says. “This will spur faster adoption of SSL technology, as it gives a sense of familiarity to the user.”

Tyco Electronics has been one of the leaders in the modular approach to SSL.

“The modular approach works when the complete subsystem has been engineered to work together,” says Rix. “Many luminaire manufacturers are baffled by the many technologies required to produce an SSL fixture—LED selection, driver electronics, thermal management, controls, and new interconnect. All these technologies must be understood and optimized for each application.”

“One of the biggest impediments to LED deployment is changing consumer behavior. Hence, using the existing infrastructure for incandescent and CFL (compact fluorescent lamp) lighting will go a long way to accelerate LED deployment,” says Sajol Ghoshal, business unit manager for advanced platform products at Texas Advanced Optoelectronic Solutions.

“The public is motivated to participate in the green energy eevolution and if that can be achieved without retooling their infrastructure, this will speed up the adoption by a significant magnitude,” Ghoshal says. “Modularity also involves simpler decision making and when combined to champion the green initiative can increase the speed of adoption significantly.”

“The retrofit market is clearly the largest market today. Replacement LED bulbs give customers a strong incentive to upgrade their existing lighting infrastructure with a more energy efficient technology,” says Brad Bullington, vice president of strategy and corporate development at Bridgelux.

“Further, since LEDs are a semiconductor technology, as LED-based modules or bulbs gain market share it opens the door to additional applications such as advanced lighting controls and a variety of sensors and detectors,” Bullington adds. “This begins to add more value to a customer’s lighting systems much in the same way iPhone apps added greatly to the value of owning a mobile phone. As perception of this added value grows it will accelerate SSL adoption.”

“Most of the calls for a modular approach to SSL boil down to two things. First, the lighting industry has had fixtures that outlive the light source for over 100 years. It is a deeply ingrained philosophy that the light source must be ‘serviceable’ because it will not last as long as the fixture housing,” says Paul Scheidt, product marketing manager for Cree LED Components.

“LED technology turns this philosophy upside down because it is conceivable that the LEDs inside a fixture could last for 30 years or longer. Most fixture makers only warranty the paint or finish of the fixture for five years. The lighting industry is just so used to ‘changing the light bulb’ that they can’t help but ask for the ability to do so,” Scheidt says.

“The second reason is that some feel that LED technology is yet unproven in long-term reliability. Keep in mind that there is 100 years of data on incandescent bulbs and 50 to 60 years on fluorescent tubes. Even five years of LED data still seems relatively short,” he adds.

Papanier is pretty much down with using existing fixtures for ease of migration.

“An easy conversion from traditional lighting to LED lighting leads to less resistance. This makes the transition easy for the user to switch over, by having less cost to convert,” he says.

“Any strategy that gives consumers a more comfortable transition to new light sources will accelerate the acceptance rate,” Emmons agrees says. “If designers are able to execute this modular approach or any other scheme that maintains a familiar environment and is retrofittable, the general public will accept new light sources more rapidly. The lighting industry has the history of slow evolution and will resist revolution. This has been borne out over the 100+ year history of artificial lighting.”

However, Schratz foresees the replacement of existing fixtures by necessity.

“The issue with LED retrofit bulbs within existing fixtures is that the ballasts are not built to handle LED-based technology,” Schratz says. “Since one of the tricks to a long-lasting LED product is to properly thermally manage the heat generated by LEDs, a new lighting fixture will give customers the best chance of realizing the potential life of an LED.”

So, it appears there’s some consensus in the industry that the modular replacement is the most viable method for initiating a speedy acceptance of SSL while at least maintaining user confidence.

“In recent years we have already witnessed the mass adoption of a new lighting technology, CFL, that uses the existing infrastructure. The general public has confidence in the existing infrastructure because it is standardized, regulated, and it works,” says Jim Hunter, vice president and general manager of global commercial markets at Luminus. “By adopting the existing infrastructure, SSL technology should be able to accelerate conversion by five to10 years.”

On the other side, in terms of consumer confidence, designers should take some caution.

“The only way this \\[modular approach\\] will elicit more confidence from the public is if the SSL luminaires provide the same efficacy provided by the luminaires they are replacing and also deliver on the promise of longer life with less energy consumption,” says Mancini.

“An important thing to note is that fixtures designed for incandescent bulbs may not offer the ventilation needed to support LED electronics, and this can drastically shorten their life to an unacceptable level. The luminaire must also deliver the exact color temperature, intensity, and lighting pattern of the lamp being replaced. These are all very difficult to accomplish, and the proposed modular approach suddenly isn’t very simple to achieve,” she says.

What’s Abetting SSL Acceptance?

Obviously, SSL companies have not been sitting on their hands waiting for consumer and commercial acceptance. They have been and are more than accommodating with products that not only ease the migration to SSL but also keep a rein on the purse strings. The overall industry approach seems to be modular by both necessity and design.

Introduced early this year to lighting manufacturers, the Nevalo SSL system from Tyco Electronics promises to quicken the transition from established light sources to LED fixtures. It consists of various plug-and-play components and evaluation tools plus a five-year system warranty (Fig. 1). It also offers more than 60 LED module options with brightness levels ranging from 300 to 3400 lumens and in form factors supporting most popular lighting applications.

Other components in the system include optics in total internal reflection and reflector styles, drivers with constant current output, dimming-control and temperature monitoring, a unique ribbon-based, four-wire configuration wiring system that is physically keyed and color coded for polarity, heatsinks matched to the LED modules, and circuit-protection devices.

Adding further value to the system, Nevalo provides a comprehensive set of design and budgeting tools that include a thermal test instrument to evaluate a system’s thermal performance and an SSL system budget calculator to help mix and match drivers and LED modules. Also, Nevalo’s Web-based product configuration tool helps users specify a system and produce a bill of materials and a drawing. Product-development kits are available for down lights, wall sconces, and track lights.

Also a modular solution, LEDtronics’ PAR-style (Parabolic Aluminized Reflector) lamps directly replace incandescents and halogen lamps that consume up to 100 W and fluorescent bulbs up to 26 W (Fig. 2). Operating more than 20 times longer than equivalent incandescent bulbs, the lamps operate either in a 120-V ac dimmable mode or with a wide input-voltage range from 90 to 290 V ac. The Edison medium screw-base and GU24 bi-pin base bulbs come in various PAR20, PAR30, and PAR38 styles with energy consumption ranging from 7 W (PAR20) through 12 W (PAR30) and up to 15 W (PAR38). Brightness ranges from 333 lumens (PAR20) to 762 lumens (PAR38).

Cree’s modular LBR-30 LED lamp claims an industry benchmark for color rendering via the company’s TrueWhite technology (Fig. 3). Intended to replace incandescent lamps in tracks, commercial, and residential recessed downlights, the lamp consumes just 12 W and specifies a color rendering index of 94. It delivers 600 lumens, equivalent to a 60-W incandescent, and lasts up to 50,000 hours in open fixtures.

Easy to use and modular, Dialight’s DuroSite LED Low Bay Fixture promises maintenance-free, high-quality light with minimal glare for near-perfect visibility in contained apps with a less than 25-ft mounting height (Fig. 4). With a power factor beyond 0.95, it delivers up to 75 lumens per watt with a total power consumption of 80 W and ensures at least 50% energy savings over high-intensity discharge (HID) sources. Available in both cool white and neutral white versions, the fixture is also available with either a variable dimmer or motion detector/occupancy sensor.

With an MSRP of $19.95, consumers may find it hard to pass up Lumiette’s Xcellume PAR 38. It not only provides the performance of an LED lamp at a CFL price, it may also be the lighting industry’s first flat-panel lamp (FPL) (Fig. 5). With a useful life of 25,000 hours, the FPL is dimmable and will fit into any existing medium screw-based socket. It consumes 15 W while producing 750 lumens, for a lumens-per-watt ratio of 50.

Component-Level Advances

Getting right down to the board, a couple offerings catch the eye. For example, the SST-90 White PhlatLight is a large-chip white LED in a surface-mount package (Fig. 6). Exhibiting high power and efficiency, it enables lighting-fixture OEMs to replace bulbs and LED arrays with a single LED. A single, monolithic die measuring nine square millimeters, the SST-90 produces 1000 lumens with a 10-W input and 2250 lumens at its maximum rated drive current. Additionally, PhlatLight LEDs have a lifetime of 60,000 hours with lumen maintenance of greater than 70%.

With an eye on retail, high-bay, roadway, exterior area, and industrial lighting apps, Bridgelux extends its LED portfolio with 3500- to 8000-lumen arrays (Fig. 7). The RS Arrays also deliver an extended range of color temperatures from 2700K to 5600K including warm, neutral, and cool white and multiple color rendering indices options.

Once again, with a commitment to market-wide migration to SSL, the arrays promise to ease and enable rapid development of high-lumen LED products and accelerate the replacement of high wattage, accelerating SSL’s ability to replace high-wattage HID luminaires.

“As we initiated the design of our Nevalo SSL System for interior lighting applications, the new additions to the Bridgelux RS Array series provided the best solution for the high-light-density versions of our new lighting module,” says Bruce Pelton, chief technology officer for the Tyco Electronics Lighting Division, coming full circle back to systems.

The Ultimate Migration

After establishing the products, which have in fact proven themselves in quality, reliability, and long-term cost effectiveness, what would be the ideal scenario for a smooth migration to all-SSL illumination? For starts, Ghoshal believes three elements are essential.

First, the industry needs high-quality LED lighting “represented accurately for the consumer by a lighting facts label, like a nutrition label. The Lighting Facts label, jointly developed by the DOE (Department of Energy) and Next Generation Lighting Industry Alliance, provides a quick simple summary of product performance data as measured by an industry standard IES LM-79-2008, reporting product performance in lumens, efficacy, watts, correlated color temperature, and color rendering index,” Ghoshal says.

Second, the migration needs “LED lighting that enhances the value of the light through Green Energy savings driven by autonomous sensor-based lighting management” and, third, a “cost point that can justify a return on investment within two years, incentivized through local utilities.”

“There will need to be some standardization, official or de facto, of SSL products,” says Rix. “Hopefully this standardization is built around the promise of what SSL can be: form factor, digital control, and real application scenarios versus just trying to replicate incandescent form factors.”

“This is not even a feasible scenario to consider,” notes Emmons. “No one lighting source is applicable to all lighting solutions. The lighting fixtures and lamp market has hundreds of thousands of SKUs and millions of installed products. In the case of indoor products, lighting fixtures last for decades. There is little incentive by the consumer to replace existing fixtures or lamps they consider perfectly acceptable.”

“The LED lighting industry is still pretty young. There is no clear business model that has proven to be the winner, so I know that anything I say could be dead wrong in a year,” cautions Scheidt. “My opinion is that LED lighting will continue to win in commercial applications and with buyers that consider the total cost of ownership of their lighting. These wins will give the industry the economies of scale that it needs to get pricing down to make LEDs more acceptable in the consumer market. What no one knows is how quickly all of this will happen.”

“The conversion to all-LED illumination will take time and strong government legislation around the world,” says Hunter. “Consumers and businesses will continue to purchase traditional lighting technologies as long as they are able because they are satisfied with the performance and don’t recognize the energy efficiency benefits of LEDs.”

Ng sees more technical issues needing resolution for a smoother ride.

“Some form of standardization in testing, measuring, and reporting is necessary to avoid misinformation and confusion in the market,” Ng says. “This would ensure the industry speaks in the same language and would help to educate users and ensure they have a good understanding of SSL technology. From a performance standpoint, an ideal scenario would be the continuous improvement in efficacy and cost reduction, such that SSL becomes a compelling option from a viewpoint of return on investment.”

Summarily in agreement with most, Schratz cites five elements.

“To allow for a smooth transition to all SSL, prices of LED bulbs and complete fixtures must be reduced, guaranteeing a two-year or less payback with a product which will certainly last five years. Also important are high-level government acceptance, continuation of rebate and incentive programs to aid customers with upfront costs, an eventual ban of all inefficient lighting technologies, carbon emission reduction goals for residents and businesses, and market education with real-life application case studies documenting all features and benefits.”

“For the general consumer, LED bulbs will need to have the same lumens as a standard light bulb in 360° of even light. Once the A19 LED bulb can achieve the same smooth light, then the consumer will have an easier time choosing to make the switch over to LEDs. A simple plug-and-play option is needed at the consumer level at a competitive cost or have the energy saving so the return on investment is obtained sooner for general room lighting applications,” says Papanier.

“Like with any new technologies it takes time and a proven track record of the new technology to be accepted,” Papanier adds. “What’s hurting the LED market is the lower-cost imported LED products that are flooding the market. This is giving LED bulbs a bad reputation. These products do not perform to consumer expectations or hold up to the light output or life data that is printed on the packaging they are packaged in.”

“The ideal scenario for a smooth migration of all-SSL illumination is that the industry needs to experience successful installations and programs that deliver on the promise of meeting expectations for energy cost savings and long life expectancy,” says Mancini.

“Luminaire designs must also be established and offer long-term availability so a commitment to a product roadmap is essential. Architects are often required to choose their lighting scheme years before a project is completed. Without the promise that a particular luminaire will be available for many years to come, architects will fall back to familiar, albeit older technologies,” she says.

It’s probably safe to surmise that a complete, smooth, and successful migration to SSL requires reliable and easy to use components, affordable components with a long lifespan, and both immediate and tangible savings for the short and long terms. Sounds like a recipe for success.

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